Sept 8 (Reuters) - Intel INTC.O announced a series of top executive changes on Monday, including the departure of products chief Michelle Johnston Holthaus, at a time when CEO Lip-Bu Tan intensifies efforts to turn around the struggling U.S. chipmaker.

Holthaus, who will leave after more than three decades with Intel, had held numerous senior leadership roles, including interim co-chief executive officer following the ouster of former CEO Pat Gelsinger last year. She will remain a strategic adviser over the coming months.

Reuters reported earlier this year that Tan seeks to flatten the company's leadership team, with most important chip groups reporting directly to him, while also slashing jobs to streamline operations.

Intel also said on Monday Kevork Kechichian has joined as executive vice president and general manager of the data center group.

A chip industry veteran, Kechichian came from Arm ARM.O, where he most recently was the executive vice president of engineering. He has also worked at NXP Semiconductors NXPI.O and Qualcomm QCOM.O.

Among other changes, Intel announced setting up of a new central engineering group, which will be led by Srinivasan Iyengar, a senior vice president. In the expanded role, Iyengar will build a new custom silicon business to serve a broad range of external customers.

Naga Chandrasekaran, executive vice president and chief technology and operations officer of Intel Foundry, will expand his role to include Foundry Services, while Jim Johnson has been appointed as general manager of Intel's client computing group.

The announcements come at an uncertain time for Intel, with U.S. President Donald Trump saying last month that the government would take a 10% stake in the company. Trump has also called for Tan to resign over conflicts of interest.